In magnetic heads used in a magnetic disk device, it has been required to reduce the area of a recording magnetic pole appearing on an air bearing surface (ABS) so as to cope with high density recording. Reducing the area of the recording magnetic pole results in the possibility that the recording magnetic pole may collapse during the process of forming the recording magnetic pole on a wafer.
As a means for avoiding such collapsing, therefore, an elongate support part is formed to extend continuously linearly from an ABS part which will appear on the ABS as a pole end face. As seen from above on the wafer midway during the manufacturing process, accordingly, the design of the recording magnetic pole is such that the elongate support part extends straight with the same width as the ABS part.
However, since the shape of the end face appearing on the ABS is determined in a photolithography process for forming the recording magnetic pole, the support part far away from the ABS has a slightly narrow frame-like shape. This results in decreasing the volume of the magnetic pole plating at the narrow, frame-shaped support part far away from the ABS, so that when a magnetic pole forming process such as CMP (chemical mechanical polishing) or milling is performed after the photolithography process, dependency may appear on the pole shape to cause pole missing. The pole missing results in variations in shape on the ABS, causing pole shape anomaly and problems such as open pole resistance or deterioration in resistance distribution, which can lead to a decrease in wafer yield. In the subsequent process (processing), moreover, the processing accuracy can be affected by in-plane pole resistance distribution, which can lead to a decrease in slider yield.
Japanese Unexamined Patent Application Publication No. 2008-181611 discloses that a planar shape of a pattern in a main pole pattern forming process is composed of; a main pole pattern having a narrow tip having a predetermined length and narrowed down from a magnetic field induction part; and a support pattern composed of a first support part having a predetermined width and length and extending from the tip of the main pole pattern with a flare part therebetween and a wider second support part extending from the first support part with another flare part therebetween.
However, since the width of the first support part is 2 to 5 times the width of the tip so as to support the tip, the difference in width between the first support part and the tip is excessively large, so that the shape change point strongly affects and makes unstable the shape of the part which will appear on the ABS as a pole end face. Between them, there is also a difference in resistance to a magnetic pole forming process such as CMP or milling, which can easily cause pole shape anomaly or the like.